Skeletal Mesh Merge with MorphTargets

Hi guys.
Iv’e been at it for weeks, but no luck. There is literally no correct answer anywhere.
I’m trying to create a modular character by merging a few skeletal meshes together, and applying their morph target values to the resulting mesh.
Documentation on this subject is extremely lacking, and no question about this subject on the forum was answered, so any help would be highly appreciated.